# Given an array of integers that is already sorted in ascending order,
# find two numbers such that they add up to a specific target number.
#
# The function twoSum should return indices of the two numbers such
# that they add up to the target, where index1 must be less than index2.
#
# Note:
#
# Your returned answers (both index1 and index2) are not zero-based.
# You may assume that each input would have exactly one solution and
# you may not use the same element twice.
# Example:
#
# Input: numbers = [2,7,11,15], target = 9
# Output: [1,2]
# Explanation: The sum of 2 and 7 is 9. Therefore index1 = 1, index2 = 2.


class Solution:
    def twoSum(self, numbers, target):

        left = 0
        right = len(numbers) - 1

        while left < right:
            total = numbers[left] + numbers[right]

            if total == target:
                return [left + 1, right + 1]
            elif total > target:
                right -= 1
            else:
                left += 1
